1. Field
The present invention relates generally to power distribution systems and, more particularly, to fault tolerant power distribution systems capable of supporting critical loads with high power requirements.
2. Description of Related Art
The electrical power requirements of buildings housing large computer centers can be very high. The difficulty in efficiently supplying such buildings with adequate power is compounded when the computers are mission critical computers that must have a constant source of uninterrupted power.
Conventionally, mission critical computers are powered using the so-called uninterruptible power supply (UPS) power circuits. The UPS circuits monitor power flowing to the electrical loads (e.g., mission critical systems), and in the event of a power failure, seamlessly route power to the loads from a backup source such as a battery. From the point of view of the computers, power was never lost and they continue to operate as normal.
Supplying UPS power to high power consumption buildings can be a daunting task. Conventionally, such UPS solutions were individually designed and implemented at each site, resulting in a relatively expensive and time consuming design and engineering task. Additionally, maintenance of the power circuitry at each such site tends to require site-specific training, thus increasing cost.
Moreover, although UPS circuits effectively handle power disruptions leading to the site, the UPS circuit itself is still subject to failure. Accordingly, in order to increase the fault tolerance of a system, multiple redundant UPS systems were conventionally installed at a site. This type of redundancy, called system plus system redundancy, implements separate and parallel power systems and power pathways all the way through the site and leading to the loads. Although fault tolerant, these systems can be expensive as every part is duplicated for each level of redundancy.
Accordingly, thus is a need in the art for an improved UPS power solution at sites having high power requirements.
Systems and methods are needed to address these needs as identified above.
One aspect of the present invention is directed to a multi-level modular power distribution system including a plurality of power modules, a plurality of transfer modules, and a plurality of power distribution modules. The power modules are each connected to receive power from an external source, the plurality of power modules including at least one alternate power module. Each of the transfer modules is associated with and connected to a corresponding one of power modules and to the at least one alternate power module. The power distribution modules receive power from the transfer modules and supply power to electrical loads of the power distribution system. When one of the power modules fails, the transfer module corresponding to the failing power module switches to power from the alternate power module.
A second aspect of the present invention is directed to a power module for supplying power in a modular power system. The power module comprises a temporary source of power; a petroleum powered backup generator; and an uninterruptible power supply (UPS). The UPS conditions power received from a main power supply and outputs the conditioned power. Further, the UPS receives power from the temporary source of power and the backup generator when the power from the main power supply fails.
Another aspect of the present invention is a method of supplying power to a building site. The method includes providing a predetermined number of power modules external to the building site, the predetermined number being at least equal to the total power requirement of the building site divided by two-thirds of the power capacity of the each power module. Further, each of the power modules is connected to associated transfer modules located within the building site. At least one of the power modules is designated as an alternate power module and connected to more than one of the transfer modules. The transfer modules are connected to distribution modules located proximate to the electric loads designated to use the supplied power.